‘Uncharted territory’: UN declares El Nino weather event as records near
By Laura Chung
Australia has been described as the most vulnerable nation in the developed world after the United Nations declared the beginning of another El Nino event.
The World Meteorological Organisation, a specialised agency of the UN, declared the El Nino event late on Tuesday night.
A huge water retention basin near Warren on the Macquarie River flood plain photographed in 2019, when Australia had one of the worst droughts on records.Credit: Wolter Peeters
“The declaration of an El Nino ... is the signal to governments around the world to mobilise preparations to limit the impacts on our health, our ecosystems and our economies,” the World Meteorological Organisation’s Secretary-General Professor Petteri Taalas said.
“Early warnings and anticipatory action of extreme weather events associated with this major climate phenomenon are vital to save lives and livelihoods.”
The agency said the El Nino was expected to be moderate in strength, but the impact of it could be much more severe.
What does an El Nino look like for Australia?
It’s one of the most important drivers of unusual weather over the entire globe. For most of Australia, El Nino brings dry weather, increasing bushfire risk. But in other parts of the world, an El Nino event leads to wetter conditions in southern America.
‘We have a dramatic season ahead, and as things will continue to unfold, Australia is the most vulnerable nation in the developed world.’
Dr Joelle Gergis from the Australian National University
The Bureau of Meteorology is yet to formally declare an El Nino event, but is expected to do so in the coming weeks. The agency has different criteria than other international weather agencies.
Three of the bureau’s four El Nino conditions have been met, including warmer ocean waters accumulating near South America, international modelling, and a certain level of air pressure difference between Tahiti and Darwin over three months. The last criterion is the weakening of equatorial trade winds, which is yet to happen.
But the bureau’s models show that by August an El Nino event will be well under way across Australia, indicating that this final climate occurrence isn’t too far off.
Scientists are concerned that, even without an El Nino, temperatures across land and sea are rising. Climate Council expert and ANU climate scientist Dr Joëlle Gergis said sea surface temperatures had already broken records this year.
She said some of the hottest sea surface temperatures had been recorded in April and May and these factors would put additional pressure on ecosystems.
The average sea surface temperature in the Australian region has warmed by 1 degree since 1900, with eight of the 10 warmest years on record occurring since 2010.
Gergis added that warmer oceans and El Ninos could lead to increased heatwaves and coral bleaching. In 2016, the Great Barrier Reef experienced the worst coral bleaching event that resulted in damage to more than 60 per cent of the region.
“This is taking us into uncharted territory,” she said. “We have a dramatic season ahead, and as things will continue to unfold, Australia is the most vulnerable nation in the developed world.”
Climate Council research director Dr Simon Bradshaw said Australia was already a land of extreme hot and dry weather, and an El Nino event amplified these conditions. It also resulted in lower rainfall for much of the continent.
“El Nino is a function of sea surface temperatures in the Pacific Ocean. The east coast of Australia is particularly affected by El Nino because of our proximity to this. Everything we see today is happening in the context of climate change; we are already living through major climate consequences,” he said.
“Everything we do to take stronger action now is limiting the future harms and is an investment in a safer future.”
The graphic below, from the National Centres for Environmental Information, shows the average temperature for previous El Nino years. In eight of the nine years shown, global anomalies remained fairly even during the 12 months. Based on that pattern, it can be assumed that this year’s average anomaly could tie with 2020 for the second-warmest year on record when a La Nina weather pattern was present.
Earlier this year, the World Meteorological Organisation released a report that said there was a 98 per cent likelihood that at least one of the next five years would be the warmest on record, beating the record set in 2015-16 when there was an exceptionally strong El Nino.
On Tuesday, the world also recorded its hottest day, when the average global temperature reached 17 degrees, surpassing the August 2016 record of 16.9 degrees.
Increasing fire risk
Former Fire and Rescue NSW commissioner Greg Mullins said there was above-normal fire potential for central Australia and northern NSW after years of heavy rain had enabled strong grass growth.
He added there had also been a lot of regeneration in parts of the state that had previously burnt in the Black Summer bushfires, elevating dangers along NSW’s South Coast. Parts of Sydney and Newcastle could also experience elevated fire risk this coming summer.
“This will set us up for a very serious fire season,” he said. “Will it be [another] Black Summer? No, because we have moisture in the ground to keep the tree canopies fairly green, but it could get serious. We are in uncharted territory.
“I am not a betting man, but if I were, I would say I bet we will see big fires this year.”
Victoria faces normal fire risk over the coming season. Data from the state government shows Victoria’s risk has decreased from last year, due to fuel reduction from the combination of planned burning and the bushfire season offsetting the regrowth in fuels since 2022.
Oceans, water and changing climate expert at the University of NSW associate professor Jan Zika said while work was going into making communities resilient, issues such as warming sea surface temperatures and sea level rises would continue to occur unless greenhouse gas emissions were reduced.
“This will become a difficult geopolitical issue later this century,” he said.
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